957
FXUS61 KBOX 110744
AFDBOX

Area Forecast Discussion
National Weather Service Boston/Norton MA
344 AM EDT Sun Aug 11 2024

.SYNOPSIS...
Comfortable conditions today and Monday, with a low chance for
a spot shower on Monday. Although there is a limited risk for
showers on Thursday, much of the rest of the workweek is
tranquil with seasonable temperatures. A frontal system moving
in from the Great Lakes could bring our next chance for
widespread showers next weekend.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
Updated: 3:30AM

Good morning! Quiet and dry to start as surface ridging develops
from the to the southwest to the northeast. Fairly light winds this
morning as surface high pressure ridges to the northeast. While not
impactful, have noticed isolated areas of radiation fog, but this is
not expected to expand or last much past sunrise. In all, we start
the day in the upper 50s to the middle 60s. Sunny conditions for the
morning will give way to a blend of sun and clouds this afternoon
due to a passing mid-level shortwave. PWATs are around an inch,
which may sound as it is enough to produce rain, but these values
are around 75% of normal. Would not be shocked if an isolate light
shower develops, but the theme is for a dry day with more mid-level
clouds this afternoon.

It is really comfortable this afternoon, with lower PWATs come lower
dew points, wide spread middle and upper 50s. Near the immediate
south coast of RI and MA these are slightly higher near 60F to 62F.
Either way, gone are those tropical dew points! This afternoon highs
are seasonable in the lower to middle 80s and if that is too warm
for your liking, the northern Worcester Hills and Berkshires will be
a touch cooler in the upper 70s.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/...
Updated: 3:30AM

Tonight: Clouds fade away post sunset and result in another cooler
night with lows in the 50s to 60F, while urban centers; Boston,
Worcester, Providence, and Hartford are lower to middle 60s.

Monday: Cooler with more clouds and during the afternoon we may see
widely scattered showers with the passage of a mid-level low and
robust shortwave. PWATs do come up a touch, but there remains a good
amount of drier air aloft. Likely to have low topped showers and
given the colder air aloft, perhaps graupel/pea sized hail given the
freezing level is around 9-10 thousand feet and 700mb temperatures
are near 0c, which is cold for mid-summer. In fact, looking at the
sounding climatology for CHH this is near the daily minimum. Looking
at the forecast soundings it shows a well mixed boundary layer, so
we will tap into those cooler temperatures. Highs are in the
70s.

&&

.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
Updated: 3:30AM

Highlights:

* Other than a chance for showers on Thurs, much of the workweek is
  dry, with seasonable temperatures.

* Possible frontal system around next weekend?

* Monitoring the tropical Atlantic for possible development in the
  Caribbean over the next 7 days. Increasing risk for rip currents
  late next weekend, but specifics otherwise are too uncertain to
  pinpoint at this time.

Details:

Little overall change in the anticipated weather regime for most of
this period per 00z ensemble mean solutions, with broad cyclonic
flow aloft and surface high pressure governing our weather pattern
at least through the workweek. While scattered showers are possible
on Thurs in vicinity of the higher terrain, associated with weak
vort energy rotating around the broad trough, it`s otherwise looking
generally dry for most of the workweek. Even these showers do not
look significant. Temps through the workweek are seasonable and
humidity levels comfortable (highs upper 70s to mid 80s, lows in the
upper 50s to mid 60s), although both will be slowly increasing by
the latter part of the workweek.

More disagreement as we move into the weekend, as the international
suite of guidance is consistent in showing an approaching shortwave
disturbance and sfc frontal system moving into interior western New
England. On the other hand, other than a handful of 00Z GEFS
members, the majority of the GEFS members and 00z GFS keep our area
dry. Maintained NBM-based slight chance PoP for the time being and
will adjust once there is better agreement between the global
models.

Besides the frontal system for the weekend, we will also need to
monitor developments in the tropical Atlantic main development
region. The National Hurricane Center (NHC) has indicated a 90%
probability of tropical cyclone development at some point over the
next 7 days from the Lesser Antilles into the Bahamas. For the
latest on this potential, refer to tropical weather outlooks from
the NHC. At the least, long-period swells propagating well ahead of
any TC that may develop, following great circle tracks, would
increase the risk for rip currents later next weekend or early in
the following workweek. Otherwise, it is way too early at this point
to provide specifics on TC potential with any degree of confidence,
but is something we`ll be monitoring.

&&

.AVIATION /08Z SUNDAY THROUGH THURSDAY/...
Forecast Confidence Levels:

Low - less than 30 percent.
Moderate - 30 to 60 percent.
High - greater than 60 percent.

Today...High Confidence.

Dry runways and VFR, mid-level clouds are between 5-7 thousand
feet this afternoon. Southwest winds around 10 knots. Should be
enough mixing to cause some 20 knot gusts this afternoon. 2kft
winds should be strong enough to preclude a sea breeze for
eastern MA terminals, including KBOS.

Tonight...High Confidence.

Continued VFR, dry weather and light winds.

Monday...High Confidence.

VFR. Low chance for a shower, mainly for terminals in CT and
western MA. West winds around 10 knots.

KBOS TAF...High confidence. SW winds should be sufficient to
hold off a seabreeze.

KBDL TAF...High confidence. VFR, light/variable winds this
morning before becoming SW Sunday afternoon.

Outlook /Monday Night through Thursday/...

Monday Night through Wednesday Night: VFR.

Thursday: VFR. Slight chance SHRA, isolated TSRA.

&&

.MARINE...
Forecaster Confidence Levels:

Low - less than 30 percent.
Medium - 30 to 60 percent.
High - greater than 60 percent.

Updated: 3:30 AM

Today through Monday...High Confidence.

* Small Craft Advisory continues for residual seas of 5 feet
  through 8AM.

Today, a weak surface wave tracks south of New England, but
precip shield will remain well offshore. Over all a mixture of
sun and clouds with good visibility and southwest winds. More of
the same on Monday, but will have a chance for spot afternoon
showers. Seas are diminishing and are generally 2 to 4 feet
during this period.

Outlook /Monday Night through Thursday/...

Winds less than 25 kt.

&&

.BOX WATCHES/WARNINGS/ADVISORIES...
CT...None.
MA...None.
RI...None.
MARINE...Small Craft Advisory until 8 AM EDT this morning for
     ANZ254>256.

&&

$$

SYNOPSIS...Loconto/Dooley
NEAR TERM...Dooley
SHORT TERM...Dooley
LONG TERM...Loconto
AVIATION...Loconto
MARINE...Loconto/Dooley